In this module, we begin a study of the influence of unbalanced forces acting
on bodies along with a study of the motion produced in bodies as a result ofunbalanced forces.

Statics versus dynamics

The earlier modules dealt with
statics . We now begin a study of
dynamics . The
study of dynamics hinges largely on three important laws of motion, which werestated by Sir Issac Newton in 1686.

Making bodies move

We know from experience that we can cause small bodies to move by pulling or
pushing them with our hands. In other words, we can cause a body to move by exerting a force onthe body. We also know that larger bodies can be caused to move by pulling or pushing
them with a machine or with a beast of burden.

We are also familiar
with the idea of falling bodies that move independently of someone pushing orpulling. We have come to know this as the result of the gravitational attraction
between masses.

Aristotle's contribution,
or lack thereof

I have never forgotten my physics professor, Brother Rudolph, at St. Mary's
University in San Antonio, Texas, telling the class that Aristotle was ahindrance to science.

Aristotle taught that heavier bodies fall faster than lighter bodies, but he
was wrong. It has been proven that all bodies fall towards the earth at the sameacceleration when the effects of air resistance are eliminated.

This is not too
difficult to prove for yourself. A small piece of paper will fall to the ground much moreslowly than a coin when the paper is in its normal state. However, if the paper is crumpled into a very tight ball,
greatly reducing the effect of air resistance, itwill fall to the ground almost as fast as the coin.

Galileo's contribution

Galileo and Newton clarified the ideas of motion through a series of
experiments. For example, Galileo discovered the important relationship between force andacceleration. He concluded that in the absence of air resistance, freely falling
objects have the same acceleration regardless of their differing weights.

Acceleration of gravity is constant

By rolling balls down inclined planes, Galileo discovered that the distance
covered under a steady force is proportional to the square of the time ofdescent. By this, he concluded that acceleration is constant, at least near the
surface of the earth.

Two cannon balls

The story goes that Galileo dropped two cannon balls of different weights off
the Leaning Tower of Pisa and observed that they struck the ground below atexactly the same time. From this, he concluded that falling bodies are subject
to the same acceleration regardless of their weight.

Inertia

By rolling a ball down one inclined plane and up a facing incline plane,
Galileo observed that the ball tended to rise to (almost) the original height on thesecond inclined plane. This was true even if the second incline plane was less
steep than the first.

This suggested that if the second inclined plane were perfectly flat, the ball
would roll forever trying to regain its original height. From this, Galileo issaid to have concluded that objects at rest tend to remain at rest, and objects
in motion tend to remain in motion with the same velocity. (Recall that a changein direction is a change in velocity.)

Questions & Answers

do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?

fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.

Tarell

what is the actual application of fullerenes nowadays?

Damian

That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.

Tarell

Join the discussion...

what is the Synthesis, properties,and applications of carbon nano chemistry

Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.

In this morden time nanotechnology used in many field .
1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc
2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc
3- Atomobile -MEMS, Coating on car etc.
and may other field for details you can check at Google

Azam

anybody can imagine what will be happen after 100 years from now in nano tech world

Prasenjit

after 100 year this will be not nanotechnology maybe this technology name will be change .
maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments

Azam

name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world

Prasenjit

how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?

Damian

silver nanoparticles could handle the job?

Damian

not now but maybe in future only AgNP maybe any other nanomaterials

Azam

Hello

Uday

I'm interested in Nanotube

Uday

this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15

Prasenjit

Join the discussion...

how did you get the value of 2000N.What calculations are needed to arrive at it